Important Interview Questions

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INDEX

1. 2. 3. 4. 5. 6. 7. 8. 9.

C# ASP.NET/ADO.NET IIS ASP2 SQL XML and WebServices COM/DCOM .Net Framework UML

ASP.NET/ADO.NET

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1. Diff between Server transfer/ Server Execute AND Response.Redirect?

Server.Transfer: End the current Web form and begin executing a new Web form. This method works only when navigating to a Web Forms page (.aspx). Server.Execute: Begin executing a new Web form while still displaying the current Web form. The contents of both forms are combined. This method works only when navigating to a Web Forms page (.aspx). Response.Redirect: Navigate to another page from code. This is equivalent to clicking a hyperlink.This for Html pages

2. Custom errors in ASP.NET

Exceptions are unusual occurrences that happen within the logic of an application. Errors that are not dealt with in code are called unhandled exceptions. Use GetLastError to get the last exception value. There are three approaches to handling exceptions in a Web application: • Use exception-handling structures to deal with exceptions within the scope of a procedure. This technique is called structured exception handling (SEH) in the Visual Studio .NET documentation. Use Try, Catch and Finally to handle Exceptions. Finally block is always executed. If an exception occurs in the “Finally" block then it becomes an Unhandled Exception. • Use error events to deal with exceptions within the scope of an object. Error events let you handle exceptions for an entire object in a single, centralized location--the error event procedure.

o Page_Error: An unhandled exception occurs on the page. This event procedure resides in the Web form. o Global_Error: An unhandled exception occurs in the application. This event procedure resides in the Global.asax file. o Application_Error: An unhandled exception occurs in the application. This event procedure resides in the Global.asax file. • Use custom error pages to display informational messages for unhandled exceptions within the scope of a Web application o Specify application-wide error page settings in the customErrors section of the Web.config file. o Specify an error page for a specific Web form in the ErrorPage attribute of the Web form's @ Page directive.

3. Pageclass life cycle and Page Events: Page_Init: The server controls are loaded and initialized from the Web form's view state. This is the first step in a Web form's life cycle. Page_Load: The server controls are loaded in the Page object. View state information is available at this point, so this is where you put code to change control settings or display text on the page. Page_PreRender: The application is about to render the Page object. Page_Unload: The page is unloaded from memory. Page_Disposed: The Page object is released from memory. This is the last event in the life of a Page object.

4. User controls vs custom controls 1. Web user controls These combine existing server and HTML controls by using the Visual Studio .NET Designer to create functional units that encapsulate some aspect of the user interface. User controls reside in content files, which must be included in the project in which the controls are used.

2. Composite Custom controls

These create new controls from existing server and HTML controls. Although similar to user controls, composite controls are created in code rather than visually, and therefore they can be compiled into an assembly (.dll), which can be shared between multiple applications and used from the Toolbox in Visual Studio .NET.

3. Rendered Custom controls These create entirely new controls by rendering HTML directly rather than using composition. These controls are compiled and can be used from the Toolbox, just like composite controls, but you must write extra code to handle tasks that are performed automatically in composite controls.

5. If we have a web service how does the client know if the location of the web 6.

service is changed?? Ans: Using the URL property. What is a DataProvider?

A data provider is a set of classes that provide access to databases. The main components of data providers are: a. Connection (SQL connection or OleDb Connection) b. Command (contains 3 methods, Execute Query,ExecuteScalar and Execute Reader) c. DataReader (This is returned when Command object's Execute Reader executes) d. DataAdapter

7. What is DataSet? The DataSet is a disconnected, in-memory representation of data. The DataSet persists in memory, and the data therein can be manipulated and updated independent of the database. A DataSet object contains DataTables, A DataSet contain

4. DataTable (each of which is an in-memory representation of a single table.) 5. DataRelations Collection (define the relationships between tables in the DataSet) And DataTables contain 6. DataColumns Collection (enumerates the columns in a particular table) 7. DataRow Collections (It contains actual Data) 8. Constraint Collection (enumerates any constraints on the table)

8. What does Command object have in ADO.Net? The Command object executes a command against a data source. It can execute non-

query commands, such as INSERT, UPDATE, or DELETE, or return a DataReader with the results of a SELECT command. The Command object is represented by two corresponding classes: SqlCommand and OleDbCommand. Command objects provide three methods that are used to execute commands on the database: • ExecuteNonQuery: Executes commands that return no records, such as INSERT, UPDATE, or DELETE • ExecuteScalar: Returns a single value from a database query • ExecuteReader: Returns a result set by way of a DataReader object

9. What are the Namespaces that ADO.Net Uses? System.Data

Classes, types, and services for creating and accessing data sets and their subordinate objects

System.Data.SqlClient

Classes and types for accessing Microsoft SQL Server databases

System.Data.OracleClient

Classes and types for accessing Oracle databases (Microsoft .NET Framework version 1.1 and later)

System.Data.OleDb Classes and types for accessing other databases 10. Differenece between DataSet and DataReader and which is faster? DataSet is disconnected in-memory representation of data, whereas DataReader is read-only, forward-only connected stream of record set. Since only one row is present in memory at a time, it presents lowest overhead, but it has to be connected for the life time of a DataReader. DataReader is faster.

11. How to deal with many-many relation ships in ADO.NET ??????????????

12. IsPostback vs viewstate? IsPostBack gets a value indicating whether the page is being loaded in response to a client postback, or if it is being loaded and accessed for the first time. true if the page is being loaded in response to a client postback; otherwise, false.

View State is the mechanism ASP.NET uses to keep track of server control state values that don't otherwise post back as part of the HTTP form. It's a hidden form field managed by the ASP.NET page framework.

13. A Windows application, say myapp.exe when complied what files are generated? 14. what is a typed dataset? If an XML schema is attached to a dataset then its called a Typed dataset.

15. What are the three Objects of ADO? The 3 objects of ADO are Command object, Connection object and Recordset object.

16. Problems in Debugging? Open Question

17. Server Side Controls and what is the diff between Server controls and HTML controls? Server controls HTML controls Server events Trigger control-specific events on the server. Can trigger only page- level events on server (postback). State management

Data entered in a control is maintained across requests.

Data is not maintained; must be saved and restored using page-level scripts.

Adaptation

Automatically detect browser and adapt display as appropriate.

No automatic adaptation; must detect browser in code or write for least common denominator.

Properties

The Microsoft .NET Framework provides a HTML attributes set of properties for each control. Properties allow you to change the control's appearance and behavior within server-side code.

18. Code behind pages? Its used for separating the code and the html. You specify in @page directive. The syntax goes like this. <% @page language=C# codebehind=”somewebform.aspx.cs” ..%> Codebehind files are pre-compiled modules written in any of the Microsoft .NET runtime compliant languages

19. What are Configuration files and how many are there? Which config file replaces web.config file? A configuration file is an XML document that contains predefined elements. An element is a logical structure. It sets the configuration information and is represented by using start and end tags. There are 3 Config files. • Machine configuration, Machine.config file. This file is located in the %runtime installation path%\Config directory and contains settings that affect all the applications that run on the machine. This file contains an element called . This element contains application-specific settings, which you can modify to define the settings required by your application. When you run an application, the runtime checks for any additions made to the system configuration file and then checks the settings in the application configuration file. • Application configuration file. This file contains the settings required to configure an individual application. For ASP.NEThosted applications, the configuration file is named Web.config and is located in the Web application folder. It contains fields like authuentication, authorization, custom errors, tracing etc.

1. Security configuration files. The security configuration files contain security permissions for a hierarchy of code groups. Code groups are logical groups of code that are related to each other through common characteristics such as application directory, strong name, URL, site, and zone. Machine.config replaces Web.config file.

20. What are differenences between OLEDB/Sql Client? OleDb is used for databases other databases like Oracle etc and also for Sql Server 6.0 or lower. SQL client is used to access Sql Server 7.0 and above.

21. What is Application and Session Handling?

The data that ASP.NET preserves between requests is called the Web form's View state. By default, a Web form's view state is available only within that Web form. To make data entered on a Web form available to other Web forms in an application, you need to save the data in a state variable in the Application or Session objects. These objects provide two levels of scope: • Application state variables

These are available to all users of an application. You can think of Application state as multipleuser global data. All sessions can read or write these variables. • Session state variables These are available only to a single session (user). Session state is like global data in a standard Windows application. Only the current session has access to its Session state.

22. what is the difference between HashTables/arrays 23.

Represents a collection of key-and-value pairs that are organized based on the hash code of the key. Arrays are a way to manage groups of similarly typed values or objects. cookies and Session difference

Cookies are used to store small amounts of information on a client. A small file that a Web application can write to the client's computer. Cookies are used to identify a user in a future session or to store and retrieve information about the user's current session. Clients might refuse cookies, so the code has to anticipate that possibility. ASP.NET stores items added to a page's ViewState property as hidden fields on the page.

24. JavaScript in Server Side Code? ???

25. Performance of Program?? 26. Assembly vs DLL created in .NET an Assembly if so why? 27. Can an assembly be an exe in .NET? Yes 28. What is use of culture info? It represents information about a specific culture including the names of the culture, the writing system, and the calendar used, as well as access to culture-specific objects that provide information for common operations, such as formatting dates and sorting strings. 29. Way of sharing sessions between ASP and ASP.NET? http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/converttoaspnet.asp

30. Can we have 2 form tags in single aspx page? Why/Whynot? ????

31. What are the lock-types available in ADO. Explain. adLockReadOnly (1) - Indicates read-only records. You cannot alter the data. adLockPessimistic (2) - Indicates pessimistic locking, record by record. The provider does what is

necessary to ensure successful editing of the records, usually by locking records at the data source immediately after editing. adLockOptimistic (3) - Indicates optimistic locking, record by record. The provider uses optimistic locking, locking records only when you call the Update method. adLockBatchOptimistic (4) - Indicates optimistic batch updates. Required for batch update mode. adLockUnspecified (-1) - Does not specify a type of lock. For clones, the clone is created with the same lock type as the original.

32. What are the cursor types available in ADO.Explain. adOpenForwardOnly (0) - Default. Uses a forward-only cursor. Identical to a static cursor, except that you can only scroll forward through records. This improves performance when you need to make only one pass through a Recordset. adOpenKeyset (1) - Uses a keyset cursor. Like a dynamic cursor, except that you can't see records that other users add, although records that other users delete are inaccessible from your Recordset. Data changes by other users are still visible. adOpenDynamic (2) - Uses a dynamic cursor. Additions, changes, and deletions by other users are visible, and all types of movement through the Recordset are allowed, except for bookmarks, if the provider doesn't support them. adOpenStatic (3) - Uses a static cursor. A static copy of a set of records that you can use to find data or generate reports. Additions, changes, or deletions by other users are not visible. adOpenUnspecified (-1) - Does not specify the type of cursor. Ex: Set Rs = Server.CreateObject("ADODB.Recordset") Rs.CursorType = adOpenDynamic

33. What is the default language of ASP. VbScript.

34. What's name of the asp.net process ? it's aspnet_wp.

35. Explain the differences between Server-side and Client-side code? Server side code executes on the server and client side code runs on the client machine. Scripts run on Client side. Client side code is written in like VBScript or JavaScript.

36. What type of code (server or client) is found in a Code-Behind class? Server side code

37. Should validation (did the user enter a real date) occur server-side or client-side? Why? The validation controls check the validity of data entered in associated server controls on the client before the page is posted back to the server. This is an important improvement to previous validation schemes--most validity problems can be caught and corrected by the user without a round-trip to the server. Server-side validation is always performed, whether or not client-side validation has occurred. This double-checking ensures that custom validations are performed correctly and that client-side validation has not been circumvented. The Field validators are Require field Validator, CompareValidator, RangeValidator et

38. What does the "EnableViewState" property do? Why would I want it on or off? EnableViewState enables the Page's ViewState to be saved between the page reuests. To turn off state management for a server control, set the control's EnableViewState property to False.

39. Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component? When there is no need for a UI to perform the required task.

40. Let's say I have an existing application written using Visual Studio 6 (VB 6, InterDev 6) and this application utilizes Windows 2000 COM+ transaction services. How would you approach migrating this application to .NET 41. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset? DataSet is a collection of Data Tables and its disconnected. A recordset looks like a single table. If a recordset is to contain data from multiple database tables, it must use a JOIN query, which assembles the data from the various database tables into a single result table. ADO is used for Connected access.

42. Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?

43. If I'm developing an application that must accomodate multiple security levels though secure login and my ASPNET web appplication is spanned across three web-servers (using round-robbin load balancing) what would be the best approach to maintain login-in state for the users?

44. What are ASPNET Web Forms? How is this technology different than 45.

what is available though ASP (0-0)? How does VBNET/C# achieve polymorphism?

Through Interface and Inheritance

46. Can you explain what inheritance is and an example of when you might use it?

47. How would you implement inheritance using VBNET/C#? 48. Whats an assembly? 49.

An assembly is a self-describing collection of code, resources, and metadata. The assembly manifest contains information about what is contained within the assembly. Describe the difference between inline and code behind - which is best in a loosely coupled solution? Code behind is loosely coupled.

Code Behind

Single File

The HTML and controls are in the .aspx file, and the The code is in <script> blocks in the same code is in a separate .aspx.vb or .aspx.cs file. .aspx file that contains the HTML and controls. The code for the page is compiled into a separate class from which the .aspx file derives.

The .aspx file derives from the Page class.

All project class files (without the .aspx file itself) are When the page is deployed, the source code is compiled into a .dll file, which is deployed to the deployed along with the Web Forms page, server without any source code. When a request for because it is physically in the .aspx file. the page is received, then an instance of the project However, you do not see the code, only the .dll file is created and executed. results are rendered when the page runs.

50. Explain what a diffgram is, and a good use for one? An XML format. Can be used by other platforms so send and receive data to a .NET application

51. Where would you use an iHTTPModule, and what are the limitations 52.

of any approach you might take in implementing one ???????? What the disadvantages are of viewstate/what are the benefits?

Because ViewState stores data on the page, it is limited to items that can be serialized. If you want to store more complex items in ViewState, you must convert the items to and from a string. 53. Describe session handling in a webform, how does it work and what are the limits? 54. How would you get ASPNET running in Apache web servers - why would you even do this?

55. Whats MSIL, and why should my developers need an appreciation of it if at all? 56. In what order do the events of an ASPX page execute As a developer is it important to undertsand these events? 57. Which method do you invoke on the DataAdapter control to load your generated dataset with data? Fill Method 58. Can you edit data in the Repeater control? Yes 59. Which template must you provide, in order to display data in a Repeater control? ItemTemplate 60. How can you provide an alternating color scheme in a Repeater control? AlternatingItemTemplate 61. What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeater control? Set the datasource property and call the DataBind method 62. What base class do all Web Forms inherit from? Page...but all .NET objects inherit form the Object Base Class. 63. What method do you use to explicitly kill a user s session? Session.Contents.Remove 64. How do you turn off cookies for one page in your site? You can't (not that I am aware of...since there is no Page level directive to do this) 65. Which two properties are on every validation control? 66. What tags do you need to add within the asp:datagrid tags to bind columns manually? Set AutoGenerateColumns Property to false on the datagrid tag 67. How do you create a permanent cookie? 68. What tag do you use to add a hyperlink column to the DataGrid? 69. What is the standard you use to wrap up a call to a Web service 70. Which method do you use to redirect the user to another page without performing a round trip to the client? 71. What is the transport protocol you use to call a Web service SOAP 72. True or False: A Web service can only be written in NET 73. What does WSDL stand for? 74. What property do you have to set to tell the grid which page to go to when using the Pager object? 75. Where on the Internet would you look for Web services? 76. What tags do you need to add within the asp:datagrid tags to bind columns manually 77. Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box? 78. How is a property designated as read-only?

79. Which control would you use if you needed to make sure the values in two different controls matched? 80. True or False: To test a Web service you must create a windows application or Web application to consume this service? 81. How many classes can a single NET DLL contain? 82. What is the role of global.asax? C#

Top

1. Abstract class/interface An Abstract class is that cannot be instantiated. An abstract class is a class that must be inherited and have the methods overridden. An abstract class is essentially a blueprint for a class without any implementation. An Interface is an abstract class with public abstract methods all of which must be implemented in the inherited classes. It's a

2. Constructors/destructors Constructors allow initialization code to perform for a class. A class constructor first creates a new instance of that class on the heap and then performs initialization.

3. What are the diff acesss modifiers are in constructors? Public, Private and Protected.

4. Design patterns? single ton, single class, dispose, finailize 5. Two places where “using” keyword is used? To use namespaces in your project we use “Using”.

6. Convert string builder class to string? A string is a sequential collection of Unicode characters, The value of the String is the content of the sequential collection, and the value is immutable. A String is called immutable because its value cannot be modified once it has been created. Methods that appear to modify a String actually return a new String containing the modification. StringBuilder class represents a string-like object whose value is a mutable sequence of characters. The value is said to be mutable because it can be modified once it has been created by appending, removing, replacing, or inserting characters. Most of the methods that modify an instance of this class return a reference to that same instance. Since a reference to the instance is returned, you can call a method or property on the

reference. This can be convenient if you want to write a single statement that chains successive operations one after another. A StringBuilder can allocate more memory as needed to store characters when the value of an instance is enlarged, and the capacity is adjusted accordingly. The amount of memory allocated is implementation-specific, and ArgumentOutOfRangeException is thrown if the amount of memory required is greater than the maximum capacity. The capacity of a StringBuilder is the maximum number of characters the instance can store at any given time, and is greater than or equal to the length of the string representation of the value of the instance. The capacity can be increased or decreased with the Capacity property or EnsureCapacity method, but it cannot be less than the value of the Length property.

7. Base, new keywords in inheritance? New keyword in C# is used to hide the implementation of the Base class and to provide a new implementation. The access modifier of the new class can be different.

8. what is Class Inheritance? We can create new classes by inheriting the features (i.e. methods and properties) of a base class along with adding our own features to represent that class as a more realistic entity. For example If class B inherits from class A, then B is said to be derived from A then the class B has all the features present in class A.

9. What languages are supported in .Net? The languages C#, C++, VB, J# are the most popular ones supported by .NET. There are around 2 dozens of languages supported by .NET to-date.

10. How do u make a function not inheritable? Sealed 11. How do u make a class not instaniable? Private 12. If a class is declared as private then who can instantiate? Where this scenario 13. 14.

comes? Nested classes. what is Protected Internal mean? See next answer If an assembly1 contains A and assembly2 contains B where B is inherited from A and A has a function which is declared as protectedInternal, then from B can u access that function?

(Interviewer said No, but in the book its said Yes) ProtectedInternal takes the intersection (He said so, but book says Union) properties of Protected and Internal. An Internal function can be accessed only from the assembly and Protected can be accessed by the types that inherit it.

15. what is inheritance and encapsulation and give examples? U know.. 16. can we use a VB.net file in code behind in a C# application? No.

17. what is global.asax? what does it contain? These files enable you to manage application-level and session-level events. These files reside in the root directory of an ASP.NET Web application or ASP.NET Web service. The Global.asax.cs or Global.asax.vb class file is a hidden, dependent file of Global.asax, which contains the code for handling application events such as the Application_OnError event.

18. Can we use session variables from asp to asp.net? Yes 19. which is better? Cookies or Viewstate? Cookies are small files which can be written to the client machine to store user preferences, login information etc. But a user might reject cookies. So there should be an alternate method if a user rejects them. But View State is a hidden value which stores the state information. I think View state is better, since a user doesn't know abt it.

20. what is caching and how many types of caching are there? Caching is the technique of storing frequently used items in memory so that they can be accessed more quickly. Caching is important to Web applications because each time a Web form is requested, the host server must process the Web form's HTML and run Web form code to create a response. By caching the response, all that work is bypassed. Instead, the request is served from the reponse already stored in memory. Use the @OutputCache page directive to cache a Web form in the server's memory. The @OutputCache directive's Duration attribute controls how long the page is cached. When used on a Web form, the OutputCache directive has two required attributes: Duration and VaryByParam. The VaryByParam attribute lets you cache multiple responses from a single Web form based on varying HTTP POST or query string parameters. VaryByParam

Cache multiple responses for a single Web form based on an HTTP POST parameter or query string.

VaryByHeader

Cache multiple responses for a single Web form based on the HTTP request header sent from the client.

VaryByCustom

Cache multiple responses for a single Web form based on a custom string.

Duration

Set the amount of time a response is cached.

VaryByControl

Cache multiple responses for a single user control based on the value of one or more controls contained in the user control.

Fragment caching is caching only parts of web form which don't change between the requests.

Applicaton Data can also be cached using Cache object.

21. what is CLR.CTS and CLS? The common language runtime can be thought of as the environment that manages code execution. It provides core services, such as code compilation, memory allocation, thread management, and garbage collection. Through the common type system (CTS), it enforces strict type-safety and ensures that code is executed in a safe environment by also enforcing code access security. The Common Language Specification (CLS) defines the minimum standards to which .NET language compilers must conform. Thus, the CLS ensures that any source code successfully compiled by a .NET compiler can interoperate with the .NET Framework.

22. diff of VS6.0 and VS.Net? VS.Net uses .Net Framework VS doesnt

23. what are Page events and Page Life cycle? A Web application lives as long as it has active sessions, whereas Web forms live for barely a moment. The life of a Web application begins when a browser requests the start page of the application. At that point, the Web server swings into action, starting the assembly (DLL) that responds to that request. The executable creates an instance of the requested Web form, generates the HTML to respond to the request, and posts that response to the browser. It then destroys the instance of the Web form. When the browser has the generated HTML, the user can type text in boxes, select options, and perform other tasks until triggering a postback event, such as a button click. Postback events cause the browser to send the page's data (view state) back to the server for event processing. When the server receives the view state, it creates a new instance of the Web form, fills in the data from the view state, and processes any events that occurred. (See Figure 2-13.) As soon as the server has finished, it posts the resulting HTML back to the browser and destroys the instance of the Web form. When the user stops using the Web application for a period of time (the default is 20 minutes), the user's session times out and ends. (See Figure 2-14.) If there are no other sessions from other users, the application ends. This doesn't always happen right away. The common language runtime (CLR) manages memory using garbage collection rather than reference counting, as OLE did. Garbage collection means that the server periodically traces through the references between objects. When the runtime finds an object that is no longer used, it throws the object away and recovers the memory. This means that you don't know exactly when an Application_End event will occur.

24. Server Controls and validation, Web Form User Controls.

25. How do u do Data Binding? 26. What are common configuration settings? Web.config, machine.config and app.config. 27. Experience with Extending ASP.NET with HTTP Handlers. 28. Experience with Extending ASP.NET with HTTP Modules. 29. Why is multiple inheritance not supported in .net? It is supported thru Interfaces. I don't why the feature is not there in .Net

30. what is the difference between declaring a variable as constant, static and read only? The first creates a compile-time constant, the second creates a run-time class constant, and the third creates a run-time object constant. The symbols you define for compile-time constants are replaced with the value of the constant at compile time. readonly values are also constants, in that they cannot be modified after the constructor has executed. readonly values are different, however, in that they're set at run time. Secondaly, you can use readonly values for instance constants, storing different values for each instance of a class type. Updating the value of a public constant is really an interface change. Updating the value of a readonly constant is easily upgradeable. Constants can be used in places where readonly values cannot, namely attributes. 31. why as strings known as immutable? Because the value cannot be changed once its initialized. The methods that look like changing the string value actually creates a new instance and stores the new value.

32. how do u register .net componenet into GAC ? Using Gacutil /I. But first the Assembly should have a Strong Name to uniquely identify the Assembly. Strong name can be created using SN.exe

33. what is GAC? Its Global Assembly cache where you u want to register your assemblies to share them across applications.

34. what r the uses os GAC? 35. What is Role Based Authentication? Role-based authorization lets you identify groups of users to allow or deny based on their role in your organization.

36. what is a Web Garden and Web Farm? A Web application running on a single server that has multiple CPUs is called a Web garden in the ASP.NET documentation. A Web application running on multiple servers is called a Web farm.

37. what is the difference between unmanaged coponenet being registered into the registry and registring managed componenet into GAC?

38. How do u maintain Session variable in WebFarm? Session data persists as the user browses through multiple pages. Session in ASP.NET is configured by the <sessionState> element, which you'll find in the web.config file in any ASP.NET project. Listing 12. Session configuration <sessionState mode="InProc" stateConnectionString="tcpip=127.0.0.1:42424" sqlConnectionString="data source=localhost; user id=sa;password=" cookieless="false" timeout="20"/> The most important attribute in Listing 12 is mode, which can be set to InProc, StateServer, or SQLServer. This attribute determines exactly where session data is stored.

39. what is ILDASM tool used for? Its used to view the assembly code.

40. What are the 3 types of authenticating a user? Windows Based, Forms Based and Passport. Windows authentication uses the security features integrated into the Windows NT and Windows XP operating systems to authenticate and authorize Web application users. The advantage of Windows authentication is that your Web application can use the exact same security scheme that applies to your corporate network--user names, passwords, and permissions are the same for network resources and Web applications. Forms authentication automatically displays a designated Web form to collect user name and password information. Code associated with that Web form authenticates and authorizes users based on a user list stored in the application's Web.config file or in a separate user database.

Passport authentication identifies users via Microsoft Passport's single sign-on service. Microsoft Passport is meant to provide Internet users with a single identity that they can use to visit a wide variety of Web sites that require authentication.

41. How do u make use of unmanaged componenets in managed code? The process of executing native code from within a .NET assembly is called platform invoke, or pinvoke for short. 1. Import the System.Runtime.InteropServices namespace. 2. Declare the unmanaged procedure using the DllImport attribute or the Declare statement. 3. Map the data types of the procedures parameters to the equivalent .NET types. 4. Call the unmanaged procedure and test its return value for success. 5. If the procedure did not succeed, retrieve and handle the exception code using the Marshal object's GetLastWin32Error method.

42. What is a type library?

43.

When you register a project for COM interop, Visual Studio automatically creates a type library for the public classes and members in the .NET assembly and registers those classes with the system registry. What is Marshalling?

When you call an unmanaged procedure from a .NET assembly, the CLR collects the parameters and converts their types in a process called Marshaling.

44. what are wrapper class used in .Net Interoperabilty? .Net Client using COM components o .Net uses Runtime Callable Wrapper (RCW) to communicate with COM components o .Net client can use COM components using the following methods ▪ Using TlbImp.exe to import the type libraries • Eg. TlbImp Mylib.tlb /out:Mylib.dll COM Clients using the .Net components .Net uses COM Callable Wrapper (CCW) for .Net components to be made available for COM clients. COM Server used Service Control Manager (SCM) to identify the COM components. In order for the SCM to locate our .Net component, it should be converted into a type library (.tlb extension). o Steps involved in making .Net components available for COM clients

▪ There is no special task needed at the time of creating .Net component ▪ Use TlbExp.exe to export .Net component to create type library • Eg. TlbExp MyLib.dll /out:Mylib.tlb ▪ Use RegAsm.exe to create type library and register it in the registry • Eg. RegAsm MyLib.dll /tlb:Mylib.tlb

45. how do u generate type library for an unmanaged componenet? Type Library Import (Tlbimp.exe) generates an Interop assembly from a COM object

46. how do u register managed componenet into registry? RegAsm.exe adds or removes system registration database entries for a .NET assembly

47. how do u make use of managed code in unmanaged programs like VB 6.0? 48. 49.

Type Library Export (Tlbexp.exe) generates a COM type library from a .NET assembly. How do u sign managed library? what r virtual functions?

Virtual functions let the functions to be overridden in the derived classes.

50. what is runtime polymorphism? With runtime polymorphism based on method overriding, the decision as to which version of a method will be executed is based on the actual type of object whose reference is stored in the reference variable, and not on the type of the reference variable on which the method is invoked.

51. how do u make an WIN 32 API function call from managed code ? P Invoke.

52. how do u debug a managed window service? ??? 53. what is tha difference between a config file and a resource file with extension 54.

.resx? how do u tamper msil code?

You can use ILDASM.exe to view the MSIL code 55. What is a session Object. A Session Object holds information relevant to a particular users session.

56. What's the implicit name of the parameter that gets passed into the class set method? Value, and its datatype depends on whatever variable we're changing.

57. How do you inherit from a class in C#? Place a colon and then the name of the base 58. 59.

class. Notice that it's double colon in C++. Does C# support multiple inheritance? No, use interfaces instead. When you inherit a protected class-level variable, who is it available to? Classes in the same namespace.

60. Are private class-level variables inherited? Yes, but they are not accessible, so 61. 62.

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looking at it you can honestly say that they are not inherited. But they are. Describe the accessibility modifier protected internal. It's available to derived classes and classes within the same Assembly (and naturally from the base class it's declared in). C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write? Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there's no implementation in it. What's the top .NET class that everything is derived from? System.Object. How's method overriding different from overloading? When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class. What does the keyword virtual mean in the method definition? The method can be over-ridden. Can you declare the override method static while the original method is nonstatic? No, you can't, the signature of the virtual method must remain the same, only the keyword virtual is changed to keyword override. But you can do that if u do Shadowing (VB.Net) or Hiding(C#). Can you override private virtual methods? No, moreover, you cannot access private methods in inherited classes, have to be protected in the base class to allow any sort of access. Can you prevent your class from being inherited and becoming a base class for some other classes? Yes, that's what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It's the same concept as final class in Java. Can you allow class to be inherited, but prevent the method from being overridden? Yes, just leave the class public and make the method sealed. What's an abstract class? A class that cannot be instantiated. A concept in C++ known as pure virtual method. A class that must be inherited and have the methods over-ridden. Essentially, it's a blueprint for a class without any implementation. When do you absolutely have to declare a class as abstract (as opposed to freewilled educated choice or decision based on UML diagram)? When at least one of the methods in the class is abstract. When the class itself is inherited from an abstract class, but not all base abstract methods have been over-ridden. What's an interface class? It's an abstract class with public abstract methods all of which must be implemented in the inherited classes. Why can't you specify the accessibility modifier for methods inside the interface? They all must be public. Therefore, to prevent you from getting the false impression that you have any freedom of choice, you are not allowed to specify any accessibility, it's public by default. Can you inherit multiple interfaces? Yes, why not. And if they have conflicting method names? It's up to you to implement the method inside your own class, so implementation is left entirely up to you. This might cause a

76. 77. 78.

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90. 91. 92.

problem on a higher-level scale if similarly named methods from different interfaces expect different data, but as far as compiler cares you're okay. What's the difference between an interface and abstract class? In the interface all methods must be abstract; in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes. How can you overload a method? Different parameter data types, different number of parameters, different order of parameters. If a base class has a bunch of overloaded constructors, and an inherited class has another bunch of overloaded constructors, can you enforce a call from an inherited constructor to an arbitrary base constructor? Yes, just place a colon, and then keyword base (parameter list to invoke the appropriate constructor) in the overloaded constructor definition inside the inherited class. What's the difference between System.String and System.StringBuilder classes? System.String is immutable; System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed. What's the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it's being operated on, a new instance is created. Can you store multiple data types in System.Array? No. What's the difference between the System.Array.CopyTo() and System.Array.Clone()? The first one performs a deep copy of the array, the second one is shallow. How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods. What's the .NET datatype that allows the retrieval of data by a unique key? HashTable. What's class SortedList underneath? A sorted HashTable. Will finally block get executed if the exception had not occurred? Yes. What's the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception? A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}. Can multiple catch blocks be executed? No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block. Why is it a bad idea to throw your own exceptions? Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project. What's a delegate? A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers. What's a multicast delegate? It's a delegate that points to and eventually fires off several methods. How's the DLL Hell problem solved in .NET? Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.

93. What are the ways to deploy an assembly? An MSI installer, a CAB archive, and XCOPY command. 94. What's a satellite assembly? When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies. 95. What namespaces are necessary to create a localized application? System.Globalization, System.Resources. 96. What's the difference between // comments, /* */ comments and /// comments? Single-line, multi-line and XML documentation comments. 97. How do you generate documentation from the C# file commented properly with a command-line compiler? Compile it with a /doc switch. 98. What's the difference between and XML documentation tag? Single line code example and multiple-line code example. 99. Is XML case-sensitive? Yes, so <Student> and <student> are different elements. 100.What debugging tools come with the .NET SDK? CorDBG - command-line debugger, and DbgCLR - graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch. 101.What does the This window show in the debugger? It points to the object that's pointed to by this reference. Object's instance data is shown. 102.What does assert() do? In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true. 103.What's the difference between the Debug class and Trace class? Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds. 104.Why are there five tracing levels in System.Diagnostics.TraceSwitcher? The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities. 105.Where is the output of TextWriterTraceListener redirected? To the Console or a text file depending on the parameter passed to the constructor. 106.How do you debug an ASP.NET Web application? Attach the aspnet_wp.exe process to the DbgClr debugger. 107.What are three test cases you should go through in unit testing? Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly). 108.Can you change the value of a variable while debugging a C# application? Yes, if you are debugging via Visual Studio.NET, just go to Immediate window. 109.Explain the three services model (three-tier application). Presentation (UI), business (logic and underlying code) and data (from storage or other sources). 110.What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET? SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it's a .NET

layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines. 111.What's the role of the DataReader class in ADO.NET connections? It returns a readonly dataset from the data source when the command is executed. 112.What does the parameter Initial Catalog define inside Connection String? The database name to connect to. 113.What's the data provider name to connect to Access database? Microsoft.Access. 114.What does Dispose method do with the connection object? Deletes it from the memory. 115.What is a pre-requisite for connection pooling? Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings. 116.what are Virtual functions? The virtual keyword is used to modify a method or property declaration, in which case the method or the property is called a virtual member. When a virtual method is invoked, the run-time type of the object is checked for an overriding member. The overriding member in the most derived class is called, which might be the original member, if no derived class has overridden the member. By default, methods are non-virtual. You cannot override a non-virtual method. You cannot use the virtual modifier with the following modifiers: static abstract override 117.what is an abstract ? Use the abstract modifier in a class declaration to indicate that a class is intended only to be a base class of other classes. Abstract classes have the following features: • An abstract class cannot be instantiated. • An abstract class may contain abstract methods and accessors. • It is not possible to modify an abstract class with the sealed modifier, which means that the class cannot be inherited. • A non-abstract class derived from an abstract class must include actual implementations of all inherited abstract methods and accessors. 118.what are the application and session events? Application_Start

The first user visits a page within your Web application.

Application_End

There are no more users of the application.

Application_BeginRequest

At the beginning of each request to the server. A request happens every time a browser navigates to any of the pages in the application.

Application_EndRequest

At the end of each request to the server.

Session_Start

A new user visits a page within your application.

Session_End

A user stops requesting pages from the Web application and their session times out. Sessions time out after a period specified in the Web.config file.

119.what are namespaces and what is namespace collision? Namespaces are a way of organizing code. They provide protection from conflicting names, sometimes called namespace collisions. This protection is especially necessary in large projects in which it is very easy for two items to accidentally have the same name. 120.what is the difference between Using and Reference? You add project references to use namespaces outside of the current project. Use the Imports statement to provide a shortcut to that namespace. The Imports statement simply provides an abbreviated way to refer to a namespace in code 121.what are delegates and why are they used? A delegate is a class that holds a reference to the method that is called when an event is fired. Delegates are types used to invoke one or more methods where the actual method invoked is determined at run time. This provides a safe way for derived objects to subscribe to events provided by their base class. Delegates also provide a way for programs to respond to asynchronous procedures. Simply put, delegates provide a way to invoke methods by their address rather than by their name. The delegate's declaration must match the signature of the methods invoked. This rule ensures that delegation is type-safe. the most important reason is that delegates provide the flexibility required for responding to events and asynchronous tasks running in separate threads. 122.what are the ways of saving state information? 1. Context.Handler object Use this object to retrieve public members of one Web form's class from a subsequently displayed Web form. 1. Query strings Use these strings to pass information between requests and responses as part of the Web address. Query strings are visible to the user, so they should not contain secure information such as passwords. 2. Cookies Use cookies to store small amounts of information on a client. Clients might refuse cookies, so your code has to anticipate that possibility.

3. View state ASP.NET stores items added to a page's ViewState property as hidden fields on the page. 4. Session state Use Session state variables to store items that you want keep local to the current session (single user). 5. Application state Use Application state variables to store items that you want be available to all users of the application. 123.what are validation controls? RequiredFieldValidator

Check whether a control contains data

CompareValidator

Check whether an entered item matches an entry in another control

RangeValidator

Check whether an entered item is between two values

RegularExpressionValidator

Check whether an entered item matches a specified format

CustomValidator

Check the validity of an entered item using a client-side script or a server-side code, or both

ValidationSummary

Display validation errors in a central location or display a general validation error description

124.what r diff isolation levels in a tansaction. ReadUncommitted

Does not lock the records being read. This means that an uncommitted change can be read and then rolled back by another client, resulting in a local copy of a record that is not consistent with what is stored in the database. This is called a dirty read because the data is inconsistent.

Chaos

Behaves the same way as ReadUncommitted, but checks the isolation level of other pending transactions during a write operation so that transactions with more restrictive isolation levels are not overwritten.

ReadCommitted

Locks the records being read and immediately frees the lock as soon as the records have been read. This prevents any changes from being read before they are committed, but it does not prevent records from being added, deleted, or changed by other clients during the transaction. This is the default isolation level.

RepeatableRead

Locks the records being read and keeps the lock until the transaction completes. This ensures that the data being read does not change during the transaction.

Serializable

Locks the entire data set being read and keeps the lock until the transaction completes. This ensures that the data and its order within the database do not change during the transaction.

125.

.NET 1. 2. 3. 4. 5. 6. 7. 8. 9.

10. 11.

Top service components (distribted components) request components in .NET Managed Class vs Un-managed code? U know. What is IL? And which tool u use to view the IL? When an application is compiled in .Net then the code is converted into Intermediate Language. Common API? Common Types? Value type and reference type. Cross Language Inheritance Cross Language Debugging and profiling. What are indexers? Indexers are called smart arrays. Indexers let an object to be used like an array. The declaration is similar to the declaration of a Property. what are References in .NET? References are Namespaces or COM objects etc which you want to use in your application. what is the difference between Value Type and Reference Type?

All the data associated with a value type is allocated on the stack. When a variable of a Value Type goes out of scope, it is destroyed and its memory is reclaimed. A variable of a reference type, on the other hand, exists in two memory locations. The actual object data is allocated on the heap. A variable containing a pointer to that object is allocated on the stack. When that variable is called by a function, it returns the memory address for the object to which it refers. When that variable goes out of scope, the object reference is destroyed but the object itself is not. If any other references to that object exist, the object remains intact. If the object is left without any references, it is subject to garbage collection.

1. What Is NUnit? NUnit is a unit-testing framework for all .Net languages. Initially ported from JUnit, the current version, 2.1 is the third major release of this xUnit based unit testing tool for Microsoft .NET. It is written entirely in C# and has been completely redesigned to take advantage of many .NET language features, for example custom attributes and other reflection related capabilities. NUnit brings xUnit to all .NET languages. instead of before aa SQL:

Top

1. How do u enforce Data Integrity in SQL? Using Constraints. 2. what are differenet constraints? NOT NULL, CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY

3. What is Save Point and Rollback action? Save point is a point within a database transaction from which you can restore the database state. 4. What are indexes, and y are they used? Indexes are database objects designed to improve query performance. Indexes are structured to facilitate the rapid return of result sets. The two types of indexes that SQL Server supports are clustered and nonclustered indexes. 5. What is clustered index and non-clustered index? A clustered index contains table records in the leaf level of the B-tree. A nonclustered index contains a bookmark to the table records in the leaf level. If a clustered index exists on a table, a nonclustered index uses it to facilitate data lookup. In most cases, you will create a clustered index on a table before you create nonclustered indexes. 6. what are deadlocks? SQL Server has an algorithm to detect deadlocks, a condition in which two connections have blocked each other. If an instance of SQL Server detects a deadlock, it will terminate one transaction, allowing the other to continue. 7. What are Transaction Logs? Every SQL Server database has a transaction log that records all transactions and the database modifications made by each transaction. 8. How many indexes you have? 9. How is error handling done? 10. what are different error codes? The two primary categories of errors are computer errors, such as an unavailable database server, and user errors. Return codes and the @@ERROR function are used to handle errors that occur when a procedure is executed. 11. How do u retrieve data using Stored procedures? 12. what are different stored procedures? There are five classes of stored procedures: system stored procedures, local stored procedures, temporary stored procedures, extended stored procedures, and remote stored procedures. 13. what are triggers? and how many are there?what does each one do?

Triggers are a special class of stored procedure defined to execute automatically in place of or after data modification. The three commands that fire a trigger are UPDATE, INSERT, and DELETE. Use triggers to extend data integrity and to implement complex business logic. 14. what are locks? A lock is an object that software uses to indicate that a user has some dependency on a resource. The software does not allow other users to perform operations on the resource that would adversely affect the dependencies of the user who owns the lock. Locks are managed internally by system software and are acquired and released based on actions that the user takes. 15. what is ddl,dml and dcl? DataDefintion language..Create, Alter and drop. Data Manipulation Language- Select, Insert, update Data Control Language - Grank and Revoke 16. what is referential inregrity? SQL Server supports four types of data integrity: entity integrity, domain integrity, referential integrity, and user-defined integrity. 17. what is a foreign key,primary key and unique key and their differences? 18. what are Hash Tables? 19. what does delete table and trunctate table do? The TRUNCATE TABLE statement is a fast, non-logged method of deleting all rows in a table. This method is almost always faster than a DELETE statement with no conditions, because DELETE logs each row deletion and TRUNCATE TABLE logs only the deallocation of whole data pages. The TRUNCATE TABLE statement immediately frees all of the space occupied by that table's data and indexes. The distribution pages for all indexes are also freed. 20. 21. 22. 23. 24.

how do you implement multiple conditions in a stored procedure? Can a Primary key be NULL? no Can a Foreign key be NULL? yes what is a Btree? what are permisson levels on a Database?

Like authentication, system stored procedures are used to manage SQL Server authorization. Use sp_grantdbaccess and sp_revokedbaccess to grant or revoke database access to a security account. These system stored procedures work with all valid security accounts, Windows

accounts, and SQL Server login IDs. Granting access is also called mapping an account to a database. You use system stored procedures to manage SQL Server authentication. Use the sp_grantlogin, sp_denylogin, and sp_revokelogin system stored procedures to manage Windows account authentication. Use the sp_addlogin and sp_droplogin system stored procedures to manage SQL Server login ID authentication. 25. What is normalization?. Explain normalization types. 26. What is the disadvantage of creating an index in every column of a database table? Do not create indexes for every column in a table, because too many indexes will negatively impact performance. The majority of databases are dynamic; that is, records are added, deleted, and changed regularly. When a table containing an index is modified, the index must be updated to reflect the modification. If index updates do not occur, the index will quickly become ineffective. Therefore, INSERT, UPDATE, and DELETE events trigger the Index Manager to update the table indexes. Like tables, indexes are data structures that occupy space in the database. The larger the table, the larger the index that is created to contain the table. Before creating an index, you must be sure that the increased query performance afforded by the index outweighs the additional computer resources necessary to maintain the index. 27. what is a Dead Lock? 28. How do u aquire a Lock? 29. What are different error codes? 30. what is the difference between User-defined function and a Stored procedure? 31. Diff between Delete and Truncate? 32. what is HAVING and Group by? 33. what are JOINS? 34. what does drop table? 35. Define a transaction. What are acid properties of a transaction? A transaction is a sequence of operations performed as a single, logical unit of work. A transaction is a process where either something completes or it fails depending on its requirements. ACID properties of a transaction A - Atomicity = The entire sequence of actions must be either completed or aborted. The transaction cannot be partially successful. C - Consistency = The transaction takes the resources from one consistent state to another. I - Isolation = A transaction's effect is not visible to other transactions until the transaction is committed.

D - Durability = Changes made by the committed transaction are permanent and must survive system failure.

36. How would you remotely administer IIS? Administer through the web browser or through the IIS Snap-in (Microsoft Suggestions)

37. What is RAID? What is it used for? RAID (Redundant Array of Inexpensive Disks) is used to provide fault tolerance to database servers. (Basically for data protection just in case a hard drive or system fails)

38. What is the disadvantage of creating an index in every column of a database table? Disadvantage is it slows down the modification of data into those columns because every time data changes in the table, all the indexes need to be updated. 39. You have a query that runs slowly, how would you make it better. But some general issues that you could talk about would be: No indexes, table scans, missing or out of date statistics, blocking, excess recompilations of stored procedures, procedures and triggers without SET NOCOUNT ON, poorly written query with unnecessarily complicated joins, too much normalization, excess usage of cursors and temporary tables. Some of the tools/ways that help you troubleshooting performance problems are: SET SHOWPLAN_ALL ON, SET SHOWPLAN_TEXT ON, SET STATISTICS IO ON, SQL Server Profiler, Windows NT /2000 Performance monitor, Graphical execution plan in Query Analyzer. Download the white paper on performance tuning SQL Server from Microsoft web site. Don't forget to check out SQL Server 2hPerformance

40. What is a bit datatype?.What is it used for? Bit data type consists of either 1 or 0 (on or off) is generally used as a boolean type where the answer is either true/false, on/off, yes/no, etc...

41. What are the three Objects of ADO? Connection, Command, Recordset (There are actually more than 3 (Primary objects are (Connection, Command, Field and Recordset) Secondary objects are (Parameters, Properties and Errors)))

42. What is the wildcard character in SQL? Let's say you want to query database with 43.

LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve 'La%'. Explain ACID rule of thumb for transactions. Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent

44. 45.

46. 47.

(data is either committed or roll back, no “in-between” case where something has been updated and something hasn't), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after). What connections does Microsoft SQL Server support? Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords). Which one is trusted and which one is untrusted? Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction. Why would you use untrusted verificaion? Web Services might use it, as well as nonWindows applications. where are the three places you can store Session variables?

6. Inside the ASP.NET runtime process (aspnet_wp.exe). This is the default option and is 7.

8.

the best choice from a performance perspective but suffers from the same problem as ASP session storage: if the Web server crashes you will lose all information. Inside a dedicated Windows Service. A Windows Service is a durable process that usually starts when the computer boots and can survive logins and logouts (in fact, IIS itself runs as a Windows Service). This technique is slower than the first option, because the ASP.NET runtime must retrieve session information from the external Service, rather than from its own process. However, this option is more durable, as session information persists even if the Web server crashes or is restarted. Inside a Microsoft® SQL Server™ database. This option is the most durable of the three. Although the second option protects against Web server crashes, session information is still lost if the entire machine crashes. Because this third option logs Session to a database (as opposed to the computer's memory), it will survive even a machine reboot. From a performance perspective, this option is by far the slowest.

48. Difference between Function and Stored Procedure? Functions MUST return value whereas stored procedure need not. Functions have the advantage of being able to be imbedded in a larger statement. XML and WebServices Top

1. What is .Net Remoting? The .NET Remoting system provides a number of services to activate objects, control the lifetime of each object, and transport messages to and from remote objects using communication channels. Communication channels are the objects that transport messages between the remote objects. 2. Can remoting object pass through a firewall? using SOAP

3. what are “Serialization Formatters”? Serialization formatters are the objects that help you to encode and decode messages that are sent to or received from a remote object. Two kinds of encoding are possible for all messages: • binary and • XML encoding. Applications in which performance is critical use binary encoding. In cases where interoperability with other remoting systems is essential, XML encoding is the preferred choice

4. What are Web Services? XML Web services are program components that allow you to build scalable, loosely coupled, platform-independent applications. XML Web services enable disparate applications to exchange messages using standard protocols such as HTTP, XML, XSD, SOAP, and Web Services Description Language (WSDL).

5. what are the 2 types of Remotable Objects? 1. Marshal-by-value objects. These objects are copied and passed by value out of the application domain.

2. Marshal-by-reference objects. The clients that use these objects need a proxy to access the object remotely.

6. How does .NET remoting work? To communicate between server objects and clients in .NET Remoting, you need to use object references of the server object in the client application. When you create an instance of the remote object using the new keyword, your client receives a reference to the server object. After obtaining the object reference, the client can call methods on the server object as if the object resides in the client's process and does not run on a separate computer. .NET Remoting uses proxy objects to allow the use of the server object in the client process. When you create an instance of the remote object type in the client application, .NET Remoting creates a proxy object and sends it to the client application. This proxy object contains references to all the methods and properties of the server object. When you call a method that is on that proxy object, the remoting system receives the call, routes it to the server process, invokes the

server object, and returns the return value to the client proxy, which returns the result to the client application.

7. what are the 2 ways of activation modes in .Net remoting system and Explain? They are Server activation and client activation. In server activation, objects are created on the server when you call a method in the server class. However, objects are not created when you use the new keyword to create an instance of the server class Client-activated objects are created on the server when you create an instance using the new keyword.

8. Adv of getting Remoting Object?? 9. What is scope of Publication in .Net remoting? Static members You cannot export static members, such as fields and methods, remotely. .NET Remoting needs instance members to enable communication between the client and server objects. Instance fields and accessors

The .NET Remoting system checks whether the object that you use is exported as a proxy object. If it is a proxy object, the client can directly access instance fields through the proxy. If the exported object is not a proxy, the proxy object provides instance accessors to the client.

Private members You cannot export private members of a remote object. Delegates

Delegates are marshal-by-value objects. The object in delegates can be a remotable object, such as a serializable object, a MarshalByRef object, or a ContextBound object.

Overriding To enhance performance, the virtual methods on an object always execute methods on an locally in the application domain in which they are called. object 10. what does it require to communicate between objects across diff boundaries? 1. A server object that exposes the functionality to callers outside its boundary 2. A client that makes calls to the server object 3. A transportation mechanism to pass the calls from one end to the other

11. What are XSL and XSLT? Differences? 12. XML Data Document Object? 13. Retrieving XML directly from SQL Server? 14. Creating Editing and Validating XML Documents? 15. Using XSL and XSLT Transformations? 16. what is WSDL? WSDL stands for Web Services Description Language.

17.

WSDL is a document written in XML. The document describes a Web service. It specifies the location of the service and the operations (or methods) the service exposes What are Singleton and SingleCall objects in Server side activation in .Net Remoting? Which one hold ViewState Information?

Singleton objects can have only one instance regardless of the number of clients they have. These objects also have a default lifetime. Therefore, if you create a server object as a Singleton object, a single instance of the server object manages all the clients. When you declare an object as a SingleCall object, the remoting system creates an object each time a client method invokes a remote object. To register a server object as a Singleton object, you specify the type of the object as WellKnownObjectMode.Singleton. Singleton holds Viewstate information.

18. what does Lease Manager do? Whenever a marshal-by-reference object is remoted outside an application domain, a lifetime lease is created for that object. Each application domain contains a lease manager that administers the leases in its domain. The lease manager periodically reviews the leases for expiration. If a lease expires, the lease manager goes through its list of sponsors for that object and asks if any of them want to renew the lease. If none of the sponsors renew the lease, the lease manager removes the lease. The object is then deleted, and garbage collection reclaims the object memory. The lifetime of an object can therefore be much longer than its lifetime lease.

19. What are .net Asynchronous programming? .NET asynchronous programming enables you to call and execute a method while the program, which calls the methods, continues to execute. This enables methods to continue executing without waiting for the called methods to finish execution, which increases the speed of applications. .NET Remoting supports asynchronous programming.

20. Difference between winforms and web forms? 21. 22.

Winforms are used for Windows based apps and WebForms are for Web based apps. Difference between Server- activation and Client-activation? Server activated objects are created when a method is called and Client activated objects are created when u create a new object using “new” keyword. What is the lifetime of Server-activation and Client-activation? Server-activated objects are objects whose lifetimes are directly controlled by the server. The server application domain creates these objects only when the client makes a method call on the object, rather than when the client calls new (New() in Visual Basic) or Activator.GetObject; this saves a network round trip solely for the purpose of instance creation. Only a proxy is created in the client application domain when a client requests an instance of a server-activated type.

Client-activated objects are objects whose lifetimes are controlled by the calling application domain, just as they would be if the object were local to the client. With client activation, a round trip to the server occurs when the client tries to create an instance of the server object, and the client proxy is created using an object reference (ObjRef) obtained on return from the creation of the remote object on the server.

23. What is Multi-threading and how do u do synchronizing? Multithreading is ability to execute various threads in a program simultaneously.

24. What are the ways you host the .Net remoting Service? 25. What are the lifetime of CAOs and SAOs? 26. If there is a Dynamic Url of a webservice then how will you use it in ur program? 27. What is Thread Pooling? 28. What are the uses of “Using” keyword? 29. Which communication channel is better? TCP or http? COM/DCOM:

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1. When you create a DCOM dll what tings do yo need to consider? 2. Diff between DCOM dll vs VB dll 3. Deploy a DCOM component? 4. Can we use COM components from .NET? yes. Pinvoke 5. What is a COM component? A COM component can be any type of external or internal object that is called to perform an operation (uploading, error handling, etc...) 6. How do you register a COM component? regsvr32 path\componentname Ex: To register a component call Help.dll, located in C:\COMObjects folder Regsvr32 "C:\COMObjects\Help.dll" To unregister Regsvr32 "C:\COMObjects\Help.dll" /u 1. Is MFC supported in .NET? MFC are supported in .NET by using the RCW (Runtime Callable Wrappers) class which wraps the MFC and can be called from .NET framework. 2. Is a destructor virtual?

We need to make destructor virtual in the class if that class is being inherited by another class which has its own destructor. Else there is no need to declare destructor as virtual.

2. What are the data types in VBScript. VBScript consists of only one data type (Variant) 9.What is a virtual root and how do you create one? Better known as Virtual Directory. Allows you to create multiple website under 1 ip address. Allows you reference another location (folder) to include additional functionality. 10. What is a database index, how do you create one, discuss it's pros and cons. Clustered and non-clustered. 11. What is the default language of ASP. VBScript 12.How do you use multiple record sets( rs.NextRecordSet ). Using rs.NextRecordset 13. As soon as you fetch a record set, what operations would you perform. Check to make sure records were returned...if so, then manipulate them. IIS 6.0 · · · · · · · · · ·

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IIS Architecture IIS Deployment Administration Administration of Web Edition Command line Interface Creating and configuring FTP Sites Creating and configuring Web Sites Creating and configuring Web Applications Working with Metabase Trobleshooting and maintenance

ASP2.

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Briefly explain how code behind works and contrast that using the inline style. - Can the action attribute of a server-side

tag be set to a value and if not how can you possibly pass data from a form page to a subsequent page. (Extra credit: Have you heard of com

dna. :-) - How would ASP and ASP.NET apps run at the same time on the same server? UML

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1. What is a Sequence Diagram? 2. What is a Class Diagram? 3. What are Collaboration Diagrams? 4. Is Sequence Diagram static or Dynamic? 5. What are Use Cases? 6. What is the difference between Use Case and a Flow Chart? 7. What is Aggregation and Composition? How are they represented? 8. What is Generalization? 9. What does 'Uses' and 'extends' mean? 10. How do you represent Synchronous and Asynchronous Messages? Real Interview Questions: Plano,Tx. 1. what are cursors? 2. what are Delegates? 3. what are multicast delegates? 4. what is DataReader and DataSet? which is faster? 5. How do u access DataRows? 6. How do u make changes from DATASet to Database? 7. what are 2 parameters of Command Object? 8. what are 4 database objects? 9. How do u merge 2 tables? 10. what is Inner join and Outer join? 11. How do u use Having and Group by? 12. How do u specify to sort in Ascending or Descending order? 13. What are value types and reference types? 14. How do you programmatically disable maximizing and minimizing window?

15. How do u programmatically set the icon of an application? 16. How do u catch errors? 17. How do u programmatically set a window to open at a position? 18. what is boxing and unboxing? 19. what is .Net remoting? 1. What is normalization? Well a relational database is basically composed of tables that contain related data. So the Process of organizing this data into tables is actually referred to as normalization. 2. What is a Stored Procedure? Its nothing but a set of T-SQL statements combined to perform a single task of several tasks. Its basically like a Macro so when you invoke the Stored procedure, you actually run a set of statements. 3. Can you give an example of Stored Procedure? - sp_helpdb , sp_who2, sp_renamedb are a set of system defined stored procedures. We can also have user defined stored procedures which can be called in similar way. 4. What is a trigger? - Triggers are basically used to implement business rules. Triggers is also similar to stored procedures. The difference is that it can be activated when data is added or edited or deleted from a table in a database. 5. What is a view? If we have several tables in a db and we want to view only specific columns from specific tables we can go for views. It would also suffice the needs of security some times allowing specfic users to see only specific columns based on the permission that we can configure on the view. Views also reduce the effort that is required for writing queries to access specific columns every time. 6. What is an Index? - When queries are run against a db, an index on that db basically helps in the way the data is sorted to process the query for faster and data retrievals are much faster when we have an index. 7. What are the types of indexes available with SQL Server? - There are basically two types of indexes that we use with the SQL Server. Clustered and the Non-Clustered. 8. What is the basic difference between clustered and a non-clustered index? - The difference is that, Clustered index is unique for any given table and we can have only one clustered index on a table. The leaf level of a clustered index is the actual data and the data is resorted in case of clustered index. Whereas in case of non-clustered index the leaf

level is actually a pointer to the data in rows so we can have as many non-clustered indexes as we can on the db. 9. What are cursors? - Well cursors help us to do an operation on a set of data that we retreive by commands such as Select columns from table. For example : If we have duplicate records in a table we can remove it by declaring a cursor which would check the records during retreival one by one and remove rows which have duplicate values. 10. When do we use the UPDATE_STATISTICS command? This command is basically used when we do a large processing of data. If we do a large amount of deletions any modification or Bulk Copy into the tables, we need to basically update the indexes to take these changes into account. UPDATE_STATISTICS updates the indexes on these tables accordingly. 11. Which TCP/IP port does SQL Server run on? SQL Server runs on port 1433 but we can also change it for better security. 12. From where can you change the default port? - From the Network Utility TCP/IP properties -> Port number.both on client and the server. 13. Can you tell me the difference between DELETE & TRUNCATE commands? - Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command. 14. Can we use Truncate command on a table which is referenced by FOREIGN KEY? - No. We cannot use Truncate command on a table with Foreign Key because of referential integrity. 15. What is the use of DBCC commands? - DBCC stands for database consistency checker. We use these commands to check the consistency of the databases, i.e., maintenance, validation task and status checks. 16. Can you give me some DBCC command options?(Database consistency check) DBCC CHECKDB - Ensures that tables in the db and the indexes are correctly linked.and DBCC CHECKALLOC - To check that all pages in a db are correctly allocated. DBCC SQLPERF - It gives report on current usage of transaction log in percentage. DBCC CHECKFILEGROUP - Checks all tables file group for any damage. 17. What command do we use to rename a db? - sp_renamedb 'oldname' , 'newname' 18. Well sometimes sp_reanmedb may not work you know because if some one is using the db it will not accept this command so what do you think you can do in such cases? - In such cases we can first bring to db to single user using sp_dboptions and then we can

rename that db and then we can rerun the sp_dboptions command to remove the single user mode. 19. What is the difference between a HAVING CLAUSE and a WHERE CLAUSE? - Having Clause is basically used only with the GROUP BY function in a query. WHERE Clause is applied to each row before they are part of the GROUP BY function in a query. 20. What do you mean by COLLATION? Collation is basically the sort order. There are three types of sort order Dictionary case sensitive, Dictonary - case insensitive and Binary. 21. What is a Join in SQL Server? - Join actually puts data from two or more tables into a single result set. 22. Can you explain the types of Joins that we can have with Sql Server? - There are three types of joins: Inner Join, Outer Join, Cross Join 23. When do you use SQL Profiler? - SQL Profiler utility allows us to basically track connections to the SQL Server and also determine activities such as which SQL Scripts are running, failed jobs etc.. 24. What is a Linked Server? - Linked Servers is a concept in SQL Server by which we can add other SQL Server to a Group and query both the SQL Server dbs using T-SQL Statements. 25. Can you link only other SQL Servers or any database servers such as Oracle? - We can link any server provided we have the OLE-DB provider from Microsoft to allow a link. For Oracle we have a OLE-DB provider for oracle that microsoft provides to add it as a linked server to the sql server group. 26. Which stored procedure will you be running to add a linked server? sp_addlinkedserver, sp_addlinkedsrvlogin 27. What are the OS services that the SQL Server installation adds? - MS SQL SERVER SERVICE, SQL AGENT SERVICE, DTC (Distribution transac co-ordinator) 28. Can you explain the role of each service? - SQL SERVER - is for running the databases SQL AGENT - is for automation such as Jobs, DB Maintanance, Backups DTC - Is for linking and connecting to other SQL Servers 29. How do you troubleshoot SQL Server if its running very slow? - First check the processor and memory usage to see that processor is not above 80% utilization and memory not above 40-45% utilization then check the disk utilization using Performance Monitor, Secondly, use SQL Profiler to check for the users and current SQL activities and

jobs running which might be a problem. Third would be to run UPDATE_STATISTICS command to update the indexes 30. Lets say due to N/W or Security issues client is not able to connect to server or vice versa. How do you troubleshoot? - First I will look to ensure that port settings are proper on server and client Network utility for connections. ODBC is properly configured at client end for connection ----Makepipe & readpipe are utilities to check for connection. Makepipe is run on Server and readpipe on client to check for any connection issues. 31. What are the authentication modes in SQL Server? - Windows mode and mixed mode (SQL & Windows). 32. Where do you think the users names and passwords will be stored in sql server? They get stored in master db in the sysxlogins table. 33. What is log shipping? Can we do logshipping with SQL Server 7.0 - Logshipping is a new feature of SQL Server 2000. We should have two SQL Server - Enterprise Editions. From Enterprise Manager we can configure the logshipping. In logshipping the transactional log file from one server is automatically updated into the backup database on the other server. If one server fails, the other server will have the same db and we can use this as the DR (disaster recovery) plan. 34. Let us say the SQL Server crashed and you are rebuilding the databases including the master database what procedure to you follow? - For restoring the master db we have to stop the SQL Server first and then from command line we can type SQLSERVER -m which will basically bring it into the maintenance mode after which we can restore the master db. 35. Let us say master db itself has no backup. Now you have to rebuild the db so what kind of action do you take? - (I am not sure- but I think we have a command to do it). 36. What is BCP? When do we use it? - BulkCopy is a tool used to copy huge amount of data from tables and views. But it won't copy the structures of the same. 37. What should we do to copy the tables, schema and views from one SQL Server to another? - We have to write some DTS packages for it. 38. What are the different types of joins and what dies each do? 39. What are the four main query statements? 40. What is a sub-query? When would you use one? a query nested within another query. 41. What is a NOLOCK? Do not issue shared locks, and do not honor exclusive locks. When this option is in effect, it is

possible to read an uncommitted transaction or a set of pages that are rolled back in the middle of a read. Dirty reads are possible. This hint only applies to the SELECT statement. 42. What are three SQL keywords used to change or set someone's permissions? 43. 44. What is the difference between HAVING clause and the WHERE clause? 45. What is referential integrity? What are the advantages of it? 46. What is database normalization? 47. Which command using Query Analyzer will give you the version of SQL server and operating system? 48. Using query analyzer, name 3 ways you can get an accurate count of the number of records in a table? 49. What is the purpose of using COLLATE in a query? 50. What is a trigger? 51. What is one of the first things you would do to increase performance of a query? For example, a boss tells you that “a query that ran yesterday took 30 seconds, but today it takes 6 minutes” 52. What is an execution plan? When would you use it? How would you view the execution plan? 53. What is the STUFF function and how does it differ from the REPLACE function? 54. What does it mean to have quoted_identifier on? What are the implications of having it off? 55. What are the different types of replication? How are they used? 56. What is the difference between a local and a global variable? 57. What is the difference between a Local temporary table and a Global temporary table? How is each one used? 58. What are cursors? Name four types of cursors and when each one would be applied? 59. What is the purpose of UPDATE STATISTICS?

60. How do you use DBCC statements to monitor various aspects of a SQL server installation? 61. How do you load large data to the SQL server database? 62. How do you check the performance of a query and how do you optimize it? 63. How do SQL server 2000 and XML linked? Can XML be used to access data? 64. What is SQL server agent? 65. What is referential integrity and how is it achieved? 66. What is indexing? 67. What is normalization and what are the different forms of normalizations? 68. Difference between server.transfer and server.execute method? 69. What id de-normalization and when do you do it? 70. What is better - 2nd Normal form or 3rd normal form? Why? 71. Can we rewrite subqueries into simple select statements or with joins? Example? 72. What is a function? Give some example? 73. What is a stored procedure? 74. Difference between Function and Procedure-in general? 75. Difference between Function and Stored Procedure? 76. Can a stored procedure call another stored procedure. If yes what level and can it be controlled? 77. Can a stored procedure call itself(recursive). If yes what level and can it be controlled.? 78. How do you find the number of rows in a table? 79. Difference between Cluster and Non-cluster index? 80. What is a table called, if it does not have neither Cluster nor Non-cluster Index? 81. Explain DBMS, RDBMS?

82. Explain basic SQL queries with SELECT from where Order By, Group By-Having? 83. Explain the basic concepts of SQL server architecture? 84. Explain couple pf features of SQL server 85. Scalability, Availability, Integration with internet, etc.)? 86. Explain fundamentals of Data ware housing & OLAP? 87. Explain the new features of SQL server 2000? 88. How do we upgrade from SQL Server 6.5 to 7.0 and 7.0 to 2000? 89. What is data integrity? Explain constraints? 90. Explain some DBCC commands? 91. Explain sp_configure commands, set commands? 92. Explain what are db_options used for? 93. What is the basic functions for master, msdb, tempdb databases? 94. What is a job? 95. What are tasks? 96. What are primary keys and foreign keys? 97. How would you Update the rows which are divisible by 10, given a set of numbers in column? 98. If a stored procedure is taking a table data type, how it looks? 99. How m-m relationships are implemented? 100. How do you know which index a table is using? 101. How will oyu test the stored procedure taking two parameters namely first name and last name returning full name? 102. How do you find the error, how can you know the number of rows effected by last SQL statement?

103. How can you get @@error and @@rowcount at the same time? 104. What are sub-queries? Give example? In which case sub-queries are not feasible? 105. What are the type of joins? When do we use Outer and Self joins? 106. Which virtual table does a trigger use? 107. How do you measure the performance of a stored procedure? 108. Questions regarding Raiseerror? 109. Questions on identity? 110. If there is failure during updation of certain rows, what will be the state?